Frangible joint



J. W. HEETER July 11, 1933.

PR'ANGIBLE JOINT Filed June 27, 1930 INVENTOR so A50 Patented July 11, 1933 I JOSEPH W. lineman, or EAsrBUrLER, PENNSYLVANIA FRANG-IB LE JOINT Application filed June 27,

My invention relates to frangible joints, and more particularly to frangible joints for well casings and the like.

After awell casing has been sunk, it sometimes becomes necessary to remove all or a part of the casing from the ground. In order to remove the upper part of the casing from the lower part after the casing has been sunk, the upper part must be broken away from the lower part. I provide a frangible joint for accomplishing this purpose.

Briefly, my device Consists of a pipe cou pling made in two separate collars which are intended to form a part of the casing. The outer periphery of the lower collar is provided with a shoulder extending around its end portion. The other collar is provided with a plurality of shoulders around the inner periphery of its end portion, which shoulders arespaced apart to accommodate the shoulder of the other pipe. The second pipe is telescoped over the first pipe so that a lap-butt-jointed' pipe coupling is formed.

The ends of the pipe coupling are welded together in such manner that the weld normally holds them together, but when a sufficient force is applied to the end of one of the collars, the weld is broken. Slots or other suitable openings are provided in one'of the collars so that when the coupling is pulled apart the abutting shoulders of the end portions slide over one another, permitting the joint to be broken.

A frangible joint is illustrated in the accompanying drawing, in which 7 Figure 1 is a view in side elevation of a coupling fora well casing; and

Figure 2 is a sectional View of the coupling taken on the line IIII of Figure Referring to the drawing, the coupling 1 consists of an upper collar 2 and a lower collar 3. The upper collar 2 is threaded at 4 for the purpose of being screwed on to the upper section of the pipe of a well casing, and the lower collar 3 is threaded at 5 so as to be screwed into a lower section of pipe of the well casing. r

The lower collar 3 is also provided with a shoulder ,6 which extends around its outer 1930; Serial no. 464,264.

periphery. The shor'ilder 6 fits into the space 7 formed by shoulders 8 and 9 that are provided within the inner periphery of the up per collar 2. The latter is telescoped over the upperend of the lower collar 3 in such manner that a lap-butt-joint is formed, which provides for a short relative movement between the upper collar 2 and the lower collar 3.

Initially, the collars are welded together at 10 to connect them rigidly together under normal conditions of use. sufficiently weak, however, so that it may be broken by the application of suflicient force such as the weight of the pipe above or by a blow on the top of the well casing of which the coupling forms a part.

The weld is made The lower portion of the upper collar 2 is I provided with a plurality of slotted openings 11 for the purpose of permitting the shoulder 8 of the upper collar to expand and slip over the shoulder 6 of the lower collar when sufficient force is applied to the casing, tending to pull the collars apart.

The coupling 1 is assembled in exactly the opposite way, thatv is, the female collar is forced over or telescoped on the male collar. The openings 11 permit the end of the collar 2 to expand so as to permit the shoulder 8 to slip over the shoulder 6. The next step in the manufacture of the coupling is to spot weld the collars'together at points 10. The coupling is then complete and is ready to be used at the proper point in and as part of a well casing.

It is to be noted that a space between the upper end of the lower collar and the upper shoulder of the upper collar is provided for the purpose of permitting a relative movement between the collars after the weld be tween them has been broken. This insures a 7 complete and satisfactory break of the weld p when this is desired. p r

A sealing ring 12of lead or the likeis disposed adjacent the upper. shoulder of the upper collar in this space for sealing the joint when the weld is broken and the collars are jammed together by the weight of the casingabove the j oint; In this manner, the coupling is made to form a watertight joint. 7 r

While I have illustrated and described a certain preferred embodiment of my inven tion, it is to be understood that it may be otherwise embodied 5 invention and the scope of the appended claims. v

I claim:

""" -\i 1. A frangible c upling for'a Well easing COHWBRSCOPHlgtUbUlELI' members hav- 1Q ing coacting abutting shoulders and a weld for normally securing saidmembers together,-

at least one of said members havingislots'extending axially throughthe end thereof to permit displacementof one of said-shoulders so that the members may\}& separated.

Within the spirit of the 2 A frangible coupling for the sections of a well casing comprising tubular tclescoping members, the interfittmg portions of said members having cooperating shoulders thereon tend ng to l] m1t relative axial move-' ment thereof, one of said members having its end slotted axiall to permit deformation of said shoulders and release of said coupling members, and a frangible weld for normally securing said members in extended relation. In testimony whereof]: have hereunto set my hand. 7

JOSEPH XV. HEETER. 

